This invention relates to improvements in a fuel pump.
Hitherto, fuel pumps of various types have been proposed. A fuel pump as an example of them is disclosed in Japanese Patent Provisional Publication No. 9-154261.
The fuel pump disclosed in Japanese Patent Provisional Publication No. 9-154261 includes a hollow casing in which a pump section and an electric motor for driving the pump section are disposed.
In the fuel pump of the above type, a terminal of a connector for connecting the electric motor to an external power source can be connected through a lead wire to a brush slidably contacted with a rotor of the electric motor thereby supplying a coil of the rotor with power; however, the lead wire is sometimes sulfidized due to sulfur contained in fuel. Accordingly, there has been a case where a tin-plating or tinning treatment is made on the lead wire in order to protect the lead wire from sulfidation. When the tin-plating or tinning treatment is made on the lead wire for the above reason, a hot dipping method has been conventionally employed. In the hot dipping method, a wire material is immersed in a molten plating material to be coated at its surface with the plating material, and then passed through a die located at an outlet (of the wire material from the plating material) so as to be finished to have a certain plating layer thickness.